Information regarding American black bear (Ursus americanus) mortality caused by disease is limited. Pneumonia is a common respiratory disease that affects many species of wildlife and can result in death. In February 2011, we investigated the death of a yearling male black bear and determined cause of death to be aspiration pneumonia. We found sections of lung were diffusely congested and edematous. A bacterial culture of lung tissue revealed numerous colonies of Klebsiella spp., Alcaligenes faecalis, Aeromonas spp., Corynebacterium spp., and Streptococcus spp. The mixed bacterial colonization of the lungs associated with minimal inflammation is consistent with terminal aspiration of gastrointestinal contents resulting in aspiration pneumonia. Documentation of aspiration pneumonia in black bears can be useful for future researchers interested in the effects of disease on bears.